1. Field of the Invention
This invention relates to a reach forklift, and more particularly to a reach forklift which has steerable load wheels and is mainly intended to attain an improvement in the efficiency of cargo work.
2. Prior Art
Conventionally, a multi-directional vehicle shown in FIGS. 57 and 58 is proposed. When the vehicle travels in the directions indicated by arrow A, caster wheels p and m are turned and then fixed in these directions so that they cannot make a turn, and a caster wheel n is allowed to turn, by hydraulically controlling cylinders provided for these wheels. In this state, a steered and driving wheel 1 is turned toward a desired direction, so that Ackerman steering can be effected.
When the vehicle travels in the directions indicated by arrow B, the caster wheels p and n are turned and then fixed in these directions so that they cannot make a turn, and the caster wheel m is allowed to turn, by hydraulically controlling the cylinders. In this state, the steered and driving wheel 1 is turned toward a desired direction, so that Ackerman steering can be effected in the same manner as described above.
In the above-described vehicle, however, the cylinders s1 and s2, link levers and the like are housed in straddle arms, so that the left and right straddle arms become larger in width. The large width of straddle arms is quite inconvenient because such a forklift is required to travel along very narrow pathways in a warehouse.
When the travel direction is to be changed from A to B or vice versa, the vehicle a is first stopped, and then a button switch or the like is pressed. The necessity of individually performing such mode switching operations makes it impossible to continuously change the travel direction. When the vehicle is steered according to the theory of Ackerman-Jeantaud, the travel direction is limited to those indicated by A or B, and the attitude of the vehicle cannot be changed with respect to other directions (for example, directions inclined at 45 degrees away from the directions of arrow A). Furthermore, the steering of the vehicle cannot be controlled in such a manner that the turning center thereof is continuously changed and located on the approximate center of the body of the vehicle. Thus, the vehicle cannot make a small turn.